From left, John Gladden, Seema Singh, Blake Simmons, and Jian Shi led the development at JBEI of a one-pot system for the ionic liquid pretreatment and saccharification of switchgrass for biofuel production. (Photo by Roy Kaltschmidt)

Sandia researchers with the Joint BioEnergy Institute (JBEI) have reported the first demonstration of a one-pot, wash-free, process for the ionic liquid pretreatment and saccharification of switchgrass. Using an imidazolium-based ionic liquid pretreatment, the Sandia team was able to liberate 81.2% glucose and 87.4% xylose over the course of a 72 hour processing cycle at 70 °C. They were then able to separate the sugars at better than 90% efficiency.

The right combination of enzyme cocktail and ionic liquid pretreatment can be used to extract fermentable sugars from switchgrass in a single, wash-free step. (Photo by Roy Kaltschmidt)

This process eliminates the excessive use of water and waste disposal currently associated with washing biomass that is pretreated with ionic liquids, drastically simplifies the downstream sugar/lignin recovery process, and enables the ionic liquid to be recycled—all factors that help drive down biofuel production costs.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.